Out of curiosity, what's your proposal for enforcing rental contract business rules on a viewer's device?
Content providers see DRM as an implementation of a movie ticket system. You know, walls, doors and a doorman that kick you out after the movie is over. Also far from honour system.
See below. In reality, this DRM has nothing to do with rental, because you can't buy same content DRM-free anyway.
And nothing should be "enforced" on user's device. It's user's, not anyone's else. Your analogy with the movie theater is invalid, because there you visit, and leave when it's finished. Here it's your private [digital] space, and no DRM junk should have any business violating your privacy for any kind of enforcement purposes.
Content providers see DRM as an implementation of a movie ticket system. You know, walls, doors and a doorman that kick you out after the movie is over. Also far from honour system.